The present invention is directed to gas discharge display panels and, more particularly, is directed to a dot matrix gas discharge display.
For several years much work has been accomplished in the development of gas discharge display panels providing a dot matrix arrangement to allow for the display of messages. The two most prominent types of gas discharge display panels are the row/column arrangements and the glow transfer arrangements.
In a row/column arrangement columns of anode electrodes and rows of cathode electrodes oriented at right angles to each other to form crossover points which provide the location of the addressable glow discharge dots in the panel. One of the principal disadvantages of the row/column arrangement is the necessity to isolate the adjacent leads to an address glow point so that cross talk is eliminated. Various approaches have been used, but each makes the display more complex in construction. Also, the necessary multitude of electrodes to operate a message readout having a row/column arrangement requires a large number of leads, contributing to a complicated driving arrangement.
The glow transfer type of gas display panel is shown, for example, in U.S. Pat. No. 4,035,689 wherein there is gas communication between the respective cellular points which are designed to provide the visible glow in a dot matrix arrangement. Therefore, a multiplexing arrangement can be utilized to have the glow transfer from cell to cell at a rate higher than can be detected by the human eye and, therefore, the number of driving circuits necessary to provide the voltage to produce the glow is significantly reduced. This is a primary basis of technology utilized by Burroughs Corporation in their Self-Scan.RTM. gas discharge display panels. However, these panels do have a limitation with respect to the brightness that they can produce since the current is limited because of the time constraints in the operation of the display due to the glow transfer operation. Also, internal structure is necessary to isolate each glow position and this adversely affects the panel viewing angle.
Consequently, it is desirable to create a dot matrix panel which provides some type of compromise between the undesirably low brightness and visibility of the glow transfer type panels, but with less driving circuitry as required in the row/column type of panels.